Coreopsis are a full sun plant. Flowering would be much improved if given all that it needs.

You can't expect a plant to perform well in less than ideal conditions. Move it to a sunnier location and give it another chance.

It is a wonderful plant in sun, mine has been blooming for weeks now. I believe you are in a warmer zone than I am. If you move it this fall you will be impressed next year. You could have added this to your original ID post.

I was wondering about that...I didn't know If I added to it, would it pop to the top or remain far back and no one would see it!? LOL And yes, SW Michigan!

This one gets more sun and still isn't blooming that well! My front yard is south facing but still has a few big trees, and the area that gets the most sun is a border with stone mulch! Apparently, this was a "thing" around these parts...every other house has stone mulch!